drop Node v16

[chimurai]

trafficstars

Describe the feature you'd love to see

• [ ] drop node 16 https://github.com/chimurai/http-proxy-middleware/blob/d3851ed0075298ea2477d4221809f5875781b66f/package.json#L101
• [ ] remove legacy req.connection https://github.com/chimurai/http-proxy-middleware/blob/fd0f5682510f4636ae115896f475310229b9b6e7/src/http-proxy-middleware.ts#L66
• [ ] use node: imports (https://nodejs.org/api/esm.html#node-imports)
• [ ] update tsconfig.ts (https://node.green/#ES2022) https://github.com/chimurai/http-proxy-middleware/blob/7141588eef57536fa8127a06a2a11097bb0a8ec0/tsconfig.json#L8

Additional context (optional)

No response